For use with the new Blogger template.
Ramani Arunachalam (rarunach[at]gmail[dot]com)
You must be comfortable with editing your Blogger template.
It is easier to convert new Blogger templates to 3 columns than classic templates. This is because the condensed form of template shown in new Blogger is easier to work with. In addition, once you add another sidebar, you can move page elements between the two sidebars easily using the Layout editor.
Follow the instructions in this page to convert to 3 columns.